泛素链修饰类型研究进展

Research progress in ubiquitin chain linkage

泛素化修饰的蛋白质底物广泛参与蛋白质降解、胞内蛋白质转运、细胞信号转导、自噬和DNA损伤修复等重要的生物学过程。泛素化修饰包括单泛素化修饰和多泛素化修饰。因泛素分子含有7个赖氨酸残基和1个N端甲硫氨酸残基,多泛素化修饰又可分为同型或异型的多聚泛素化修饰。此外,泛素分子的乙酰化修饰和磷酸化修饰大大增加了泛素链的复杂性。不同泛素链的形成往往依赖泛素连接酶或者去泛素化酶。现综述不同类型的泛素链修饰类型的编辑、识别、去除机制及其生物学功能,并讨论泛素分子自身的乙酰化和磷酸化修饰。

Protein ubiquitination is widely involved in multiple celluar processes, such as protein degradation, intracellular protein trafficking, cellular signaling transduction, autophagy and DNA damage responses. Ubiquitin modification includes monoubiquitination and polyubiquitin modification. Since ubiquitin contains seven lysine residues and one N-terminal methionine residue, the ubiquitin chains are divided into homotypic or heterotypic linkages. In addition, ubiquitin acetylation and phosphorylation improve the complexity of ubiquitin chains. There are a series of ubiquitin ligases and deubiqutinases editing different ubiquitin chains. This review focuses on different ubiquitin linkage types to discuss how they are formed, recognized and erased, and what biological functions they have. The acetylated and phosphorylated ubiquitins are also discussed.